Respiratory illnesses (e.g. community-acquired pneumonia, influenza and SARS) are a major public health concern.
Severe acute respiratory syndrome (SARS) emerged in late 2002 from its purported origins in Guangdong Province, China and infected over 8400 persons worldwide to date with an accompanying case fatality rate of approximately 11% (1-4, World Health Organization, http://www.who.int/csr/sars/country/en/country2003—08—15.pdf).
A novel coronavirus (CoV), causing a spectrum of disease ranging from non-specific flu-like symptoms and lung inflammation to acute respiratory distress syndrome (ARDS) requiring intensive care, has been identified as the etiologic agent of SARS (5-8). While the SARS CoV epidemic of 2003 was largely contained through public health measures, it is unknown whether or not human SARS CoV will cause another global outbreak. With the confirmation of new unrelated SARS cases in China (9) and the finding that SARS CoV-related viruses infected persons in Hong Kong at least 2 years prior to the 2003 outbreak (10), it is clear that SARS will not easily be eradicated and that jumps from animals to humans will continue.
Lungs from patients with severe SARS show extensive acute injury with diffuse alveolar damage, acute vascular and endothelial injury and extensive immune infiltration (11-13). The molecular, cellular and pathological determinants that lead to lung injury and poor outcome in SARS are presently unclear; however the severity of SARS CoV infection may be partially determined by the immune system and dysregulated proinflammatory cytokines and chemokines (14-16).